Telegraph ciphering key tape machine



Aug. 20, 1946.

m I 7 X R. D. PARKER Filed May 21, 1942 3 Sheets-Sheet 1 FIG. I

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r 'r 3 I 2 Q z g I: j/Z 7* AMPLIFIER AND 4 RELAY UN/T Hi '26 GEAR GEARBOX 801' 24 4 5 2 MAGNET/G PERFORA TOR -z-J2 v ROTARY DISTRIBUTOR INI/EN TOR R 0. PARKER ATTORNE V 20 1946- R. D. PARKER 2,406,031

TELEGRAPH CIPHERING KEY TAPE MACHINE Filed May 21, 1942 z Sheets-Sheet 2T m A.

Ron if o/sm/au f MAGNET/C PERFORATOR AMPLIFIER AND RELAY wv/r HOUSING INl/E N TOR y R. 0. PARKER A T TORNE V Aug.- 20, 1946.

I R. D; PARKER TELEGRAPH CIPHERING KEY TAPE MACHINE Filed May BL, 1942 3Shets-Sheet 5 BALL 'u v/r AWL/HER b ncur'umr INVENTOR R D. PARKERATTORNE V Patented Aug. 20.1946

UNiTso STATES PATENT osrics TELEGRAP H CIPHERING KEY TAPE MACHINE'Ralzemond B. Parker, Brooklyn, N. Y., assignor to Bell TelephoneLaboratories, Incorporated, New

York, N. Y., a corporation of New York Application May 21, 1942, SerialNo. 443,909

' 8 Claims.

This invention relates to secret telegraph systems and particularly tothe full mechanical production of a purely random key tape for use inenciphering and deciphering permutation code teletypewriter signals.

In a system of secret telegraphy presently known in the art inconnection with which this invention may be used, the enciphered codeelements as transmitted are the resultants of the elements of theregular Baudot code signal modified by the elements of what is known inthe art as a key tape. The key tapes ar prepared and supplied to eachterminal in advance. The key tapes at each terminal are operated insynchronism. Each character element of the enciphered code may be mademarking or spacing by suitable mechanism, depending upon whether eachelement of the regular permutation code representing the character andthe corresponding element as randomly punched in the key tape are alikeor unlike.

Previous proposals for making random ciphering or key tapesor equivalentdevices have followed two general procedures.

In accordance with one procedure,tapes have been prepared at randommanually by operators. This method has two undesirable features. First,it is laborious and time-consuming. 'Second, it seems doubtful whether ahuman operator can actually prepare a mathematically random tape and thedeviations from randomness may be such as to aid unauthorized parties indeciphering messages. In any case, the efiort to make it randomincreases the laboriousness of the task and adds a mental strain to thework.

In accordance with the second procedure, tapes have been preparedmechanically. Presently known mechanical devices, however, do not infact produce mathematically random tape and, moreover, such devicesgenerally are complex and expensive to construct. As a result, few, ifany, such devices have been suitable for or applied to the making oftape. The invention herein insures the provision of purely random tape.The invention therefore promotes secrecy by insuring that the symbolspunched in the tape do not follow any recurring pattern. The elementspunched in the key tape in accordance with this invention, in otherwords, are purely random. Further, the key tape is produced entirelymechanically and, its production does not require any manualmanipulation whatsoever.

In accordance with this invention, equal numbers of two kinds of. ballsare thoroughly mixed and thereafter selected in random sets of five.

The key tapes are punched in accordance with the random selections. Thisprovides purely random tape. If a tape having a controlled bias isdesired it may be obtained by varying the numbers of the two kinds ofballs relative each to the other as desired.

An object of this invention is the preparation of key tapes forenciphering and deciphering permutation code teletypewriter signals ina'purely random fashion.

A further object of this invention is the preparation of purely randomkey tape for enciphering and deciphering permutation code teletypewritersignals entirely b mechanical means.

The invention may be understood from the following description when readwith reference to the drawings herein in which:

Fig. 1 shows a side elevation of the apparatus; Fig. 2 is a plan view ofthe apparatus; and

Fig. 3 shows the control circuit and tape punch selecting apparatus.

Refer now to Figs. 1 and 2.

A large number of balls I, comprising equal numbers of two differentkinds, are employed in this invention. Exactly half of the balls areopaque and exactly half are translucent. The balls are poured into ahopper 2. The balls are thoroughly stirred by a spiral worm 3. The wormis driven by a motor 4 and shaft 5 through a gear box 6 which rotatesthe vertical shaft 1 to which the worm 3 is rigidly secured. The shaftis held in position by bearing 18, fixed to the upper wall of gear box6, bearing 19 secured to the lower portion of hopper 2 and bearing 8which is integral with the horizontal bracket 9 secured to theright-hand wall of hopper 2 by bolts 12.

For aninterval before tape is to be prepared, power is supplied fromsource It! to motor 4 and the stirring mechanism comprising spiral worm3 is operated to insure thorough mixing of the two kinds of balls. Thebottom of the hopper H is an inclined plane sloping downwardly to theright. The lower portion l2 of the right-hand wall of hopper 2 isextended and inclined downwardly toward the right, generally parallel atthe bottom incline plane I I of hopper 2 and spaced therefrom to formtherewith a chute. The balls gravitate at random into the chute which isarranged to accommodate five rows of balls extending downwardly to theright to the position of the transverse barrier I 3 interposed in thepaths of the five rows of balls.

The mechanism thus far described will effect the random selection at thebarrier I3 of five tions to correspond, the invention may be applied tothe manufacture of tape for permutation codes having six elements. Thereis no limit to the number of elements in a permutation code for whichcorresponding selections may bem'ade in accordance with this invention.Further'theinvention may be applied to a wide variety of uses other thanthe punching of tape.

The two kinds of balls need not necessarily be present in exactly equalnumbers. They may be present in unequal numbers and the relative numbersmay be varied at will from time to time to produce what might be termedan opaque. bias or a translucent bias. Thiswouldnot be a de-' parturefrom the principle of the invention unless the bias became considerable,Consequently, g

approximate equality of the two is all that is required.

It is pointed out, however, that as the number of one kind or the otherof the two kinds of balls becomes preponderant a corresponding. bias isintroduced.

An electro-optical system comprising five similar sets of equipment isfixed in position immediately to the left of barrier l3. Each of thekinds of balls five sets of equipment comprises a lamp or other sourceof light, such. as M, a lens l5, and aperture IE in the extension I2, anaperture IT in the bottom inclined plane of the hopper, a displaceableaperture I8 inthe common shutter, and a photoelectric cell 20.

Light from the lamp I4 is directed by means of the lens at a ball whichmomentarily occupies a position adjacent the barrier l3 in one of thefive rows. Depending upon whether the ball is translucent or opaque, thelight will be passed or prevented from passing through the ball. Lightwhich passes will pass also through the aperture H and, when shutter I9isproperly positioned in a manner to be described below, the light willenter a photoelectric cell 20.

By means of photoelectrical circuit to. be described hereinafter, aperforating punch corresponding to a particular ball will be operated orprevented from operating to control the perforation of a tape in acorresponding position. Five punching magnets are controlled in thisfashion.

After the punching has been effected the barrier i3 is operated in amannertoxbe described also hereinafter. The five balls which controlledthe operation of the punching mechanism for a particular character passthe barrier and drop through the return chute 2i sloping generallydownward to the left.

In order to return the balls to the hopper the mechanism is equippedwith anendless belt 22 driven by gears 23 through shaft 24, gear box 6,shaft 5 and motor 4.

The endless belt is supported at the'top by a pulley 2'! which rotatesfreely on a horizontal shaft 28 rigidly secured in any convenientmanner. Spaced from the belton each side and at the top and bottomthereof is a guard .29 having an opening 30 above the top of the-hopper.

Securedrto the belt 22 are a'seriesof transverse members projectingat'right angles to 4 the belt. Preferably the transverse sections formedby successive right-angle members 25 are separated into five individualcompartments by means of vertical walls 26.

The balls are rolled into the individual compartments by gravity and areelevated by the continuous belt which moves in the direction indicatedby the arrows. When the balls reach the position of the opening they arerolled out of their compartments and into the hopper where they areagain mixed with the large mass of balls by the helical worm 3.

The associated. circuit which controls the shutter 19 of the opticalsystem as well as barrier i3 and the perforator 3| will now bedescribed. Refer to Fig. 3. A rotary distributor 32, having a rotatingarm 33 equipped with brushes 34a to 34e which engage a continuousconducting ring 35 and a plurality of segmented rings 36, 31, 38 and 39,is employed to control the operation of the shutter IS, the ,barrierl3and the perforator 3|. The rotating arm 33 of the rotary'distrib utor 32is rotated by means of a shaft 740 which is connected through gear box4| and'shaft. 42 to the motor 4. Brushes 34a to 346 are allinterconnected in parallel. Battery v43 is connected by means ofconductor 44 to solid ring 35. As the rotary arm 33 is rotated, theinsulating gaps between the rings are bridged by means of the brushes.Each of the segmented rings, has a conductor connected to one of itssegments which extends to an operating circuit. When rotary arm .33 isin the position shown, all of the circuits extending from therotarydistributor rings are deenergized as the brushes are not in posi tion toextend the circuit from battery connected to solid ring. 35 to segments46, 41 4B or 49. As arm 33 moves in a clockwise direction, when brushes34a and 34b form a bridge between the ring 35 and se ment 46, a circuitis established from battery 43 through conductor 44, ring 35, brush 34a,brush 34b,.jsegment 46, conductor 55, and the winding of magnet 5| toground, energizing magnet 5| which attracts armature 'l I, rotating itina clockwise direction about pivot 12. The left-hand. end of armature 'His secured by means of pin 13 tothe bottom end 'of shutter l9 which ismoved"downwardlyithrough guides 14. and 15, tensioning spring 52. Whenshutter l9is moved to its lower position the multiple apertures 18 arepositioned so as to permit light to pass. Such of the balls I as aretranslucent will permit lightto pass. Those of'them that are opaque willprevent the passage of light.

When the manual switch 53 is closed a circuit is established from.battery 54 through switch 53 and resistance 55 to the anodes 5B of thefive photoelectric cells 20 in parallel. In the case of cells associatedwith translucent balls, a current will fiow through conductors 51 andresistances 58 to ground, making the potential ofthe grid of theassociated three-element vacuum tube 59; normally non-conducting, morepositive; This, in turn, permits current to flow in the associatedvacuum tube plate circuit through the winding of the associated relay60. The various relays of the group 60 will be operated or unoperated,depending upon whether the corresponding ball I is translucent oropaque. Each operated relay closes a correspondingcontact 6 I.

I When the rotary arm 33 has moved into position ment 4T, resistance63,'thrbughsucl-lcontacts '6! as are closed and through the winding ofmagnets 64 associated with such closed contacts to ground, energizingmagnets 64 corresponding to translucent balls I. Magnets 64 positionpunches, not shown, in the perforator in position to punch ahole in acorresponding position of the tape in a well-known manner. When therotary arm 33 moves into position sothat brush 34d engages segment 48, acircuit is established from battery 43 through conductor 44, ring 35,brush 34a, brush 34d, segment 48, conductor 16 and the winding of hammermagnet 66 to ground,

operating hammer magnet 66. The operation of the hammer magnet 66operates the punches which have been set in the punching position bysuch magnets 64 as have been energized, Tape 61 will be punched incorresponding positions in a well-known manner.

When rotary arm 33 has moved into position so that brush 34c engagessegment 49, a. circuit is established from battery 43, through conductor44, ring 35, brush 34a, brush 34c, segment 49, conductor 61, and thewinding of barrier magnet 69 to ground, energizing barrier magnet 68.The operation of barrier magnet 66 rotates the bail barrier l3 about itsfixed pins 69 and 10. This permits the five balls which determine thesetting of the punch magnets to escape. As the various brushes of rotaryarm 33 move off segments 46, 41, 48 and 49 the corresponding magnets aredeenergized. Shutter I9 is restored to its original position by spring52. The relays 60 which have been energized are deenergized, openingtheir corresponding contacts 6|. The respective associated magnets 64are deenerglzed. Hammer magnet 66 is deenergized. Barrier magnet 68 isdeenergized and barrier I3 is restored. The restoration of barrier I3 istimed so that not more than one row of balls escapes into chute 2| oneach cycle.

What is claimed is:

1. In a telegraph system, the method of preparing a key tape forenciphering permutation code telegraph signals which comprises: mixingequal numbers of two different forms of an object selecting at random anumber of said mixed objects corresponding to the number of elements inthe particular code and controlling the perforations of said tape inaccordance with said selections.

2. In a telegraph system, the method of preparing a key tape forenciphering permutation code telegraph signals which comprises: (1)mixing equal numbers of two different forms of,

6 an object and selecting at random a number of said objectscorresponding to the number of elements in the particular code; (2)selectively controlling a plurality of tape perforating elements throughan electromechanical device dependent upon the random selection of saidobjects.

3. In a telegraph system, a completely automatic, purely randomlycontrolled device for preparing key tape for enciphering permutationcode teletypewriter signals comprising a, container, a plurality ofequal numbers of two different kinds of objects in said container, meansfor mixing said objects, means for randomly selecting a number of saidmixed objects corresponding to the number of variable elements in aparticular permutation code, a plurality of tape perforating elementsand means for controlling the operation of said elements dependin uponsaid random selections.

4. In a telegraph system, means for making purely random selections oftwo kinds of objects and means for controlling a tape perforator inresponse to said selections.

5. In a telegraph system, a tape perforator, an object mixing machine,means for making random selections of more than one class of objectsmixed by said machine and means for controlling said perforator inaccordance with the natures of the objects selected.

6. In a telegraph system, in combination, a device for making randomselections, at photoelectric cell controlled by the selections of saiddevice and a tape perforator responsive to said photoelectric cell.

7. In a telegraph system, a container, an equal number of two difierentkinds of units in said container, a device for thoroughly intermixingsaid units, a selection device for randomly selecting a number of saidunits corresponding to the number of variable units in a particularpermutation code and means responsive to the selection of one of saidkinds of units for operating a tape perforating punch.

8. A permutation code 7 selector comprising means for controlling afixed number of elements each of which is conditionable in a definitenumber of difierent ways, a series of bodies having individual degreesof translucency variable in number equal to said definite number, andmeans for utilizing said bodies in successive groups of said fixednumber for conditioning groups of said fixed number of elementsselectively.

RALZEMOND D. PARKER.

